Antonin Scalia, who combined a zest for intellectual combat with a vast talent for friendship, was a Roman candle of sparkling jurisprudential theories leavened by acerbic witticisms. The serrated edges of his most passionate dissents sometimes strained the court's comity and occasionally limited his ability to proclaim what the late Justice William Brennan called the most important word in the court's lexicon: "Five." Scalia was, however, one of the most formidable thinkers among the 112 justices who have served on the court, and he often dissented in the hope of shaping a future replete with majorities steeped in principles he honed while in the minority.

Those principles include textualism and originalism: A justice's job is to construe the text of the Constitution or of statutes by discerning and accepting the original meaning the words had to those who ratified or wrote them. These principles of judicial modesty were embraced by a generation of conservatives who recoiled from what they considered the unprincipled creation of rights by results-oriented Supreme Court justices and other jurists pursuing their preferred policy outcomes.

Today, however, America's most interesting and potentially consequential argument about governance is not between conservatives and progressives but among conservatives. It concerns the proper scope of the judicial supervision of democracy.

Scalia worried more than some other conservatives do about the "counter-majoritarian dilemma" supposedly posed by judicial review  the power of appointed justices to overturn the work of elected legislators. Many Scalia-style conservatives distill their admiration into a familiar phrase of praise: "judicial restraint." Increasing numbers of conservatives, however, reason as follows:

Democracy's drama derives from the tension between the natural rights of individuals and the constructed right of the majority to have its way. Natural rights are affirmed by the Declaration of Independence; majority rule, circumscribed and modulated, is constructed by the Constitution. But as the Goldwater Institute's Timothy Sandefur argues, the Declaration is logically as well as chronologically prior to the Constitution. The latter enables majority rule. It is, however, the judiciary's duty to prevent majorities from abridging natural rights. After all, it is for the securing of such rights, the Declaration declares, that "governments are instituted among men."

Scalia's death will enkindle a debate missing from this year's presidential campaign, a debate discomfiting for some conservatives: Do they want a passive court that is deferential to legislative majorities and to presidents who claim untrammeled powers deriving from national majorities? Or do they want a court actively engaged in defending liberty's borders against unjustified encroachments by majorities?

This is an overdue argument that conservatism is now prepared for because of Scalia's elegant mind. He was crucial to the creation of an alternative intellectual infrastructure for conservative law students. The Federalist Society, founded in 1982, has leavened the often monochrome liberalism of law schools, and Scalia has been the jurisprudential lodestar for tens of thousands of students in society chapters coast to coast.

Students of the court understand that, given Sen. Harry Reid's demonstrated disdain for Senate rules, if Republicans had not won Senate control in the 2014 elections, the Nevada Democrat as majority leader would very likely now extend the institutional vandalism he committed in 2013. Then he changed Senate rules, by a simple majority vote and in the middle of a session, to prevent filibusters of judicial nominees other than Supreme Court nominees. This enabled President Obama to pack the nation's second-most important court, that of the U.S. Court of Appeals for the District of Columbia Circuit. Were Reid still majority leader, the Senate's only rule would be the whim of the majority of the moment, and his caucus would promptly proscribe filibusters of Supreme Court nominees.

One consequence would be this: The United States today is one Supreme Court vote away from a radical truncation of the First Amendment's protection of freedom of speech. A Democratic president in 2017 would nominate to replace Scalia someone pledged to construe the amendment as permitting Congress to regulate political campaign speech, which would put First Amendment jurisprudence on a slippery slope to regarding all speech as eligible for regulation by the administrative state.

Scalia lived 27 years after the person who nominated him left office, thereby extending the reach of Ronald Reagan's presidency and reminding voters of the long-lasting ripples that radiate from their presidential choices. A teacher, wrote Henry Adams, attains a kind of immortality because one never knows where a teacher's influence ends. Scalia, always a teacher, will live on in the law and in the lives of unnumbered generations who will write, teach and construe it.